From 5a7f2a4f1f2fb03d9f72fc0134b00648ec02ffde Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Tue, 2 Jun 2015 17:02:56 +0200
Subject: [PATCH] Restore light attenuation settings

---
 apps/openmw/CMakeLists.txt            |  2 +-
 apps/openmw/mwrender/animation.cpp    | 28 +++++++++++++++++++++------
 components/sceneutil/lightmanager.cpp | 24 +++++++++++++++++++++++
 components/sceneutil/lightmanager.hpp |  3 +++
 4 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/apps/openmw/CMakeLists.txt b/apps/openmw/CMakeLists.txt
index 015d0db9a..bb71cb6c9 100644
--- a/apps/openmw/CMakeLists.txt
+++ b/apps/openmw/CMakeLists.txt
@@ -23,7 +23,7 @@ add_openmw_dir (mwrender
     actors objects renderingmanager animation rotatecontroller sky npcanimation vismask
     creatureanimation effectmanager util renderinginterface pathgrid rendermode weaponanimation
     bulletdebugdraw globalmap characterpreview camera localmap water
-#    occlusionquery shadows ripplesimulation refraction terrainstorage
+#    occlusionquery shadows ripplesimulation terrainstorage
     )
 
 add_openmw_dir (mwinput
diff --git a/apps/openmw/mwrender/animation.cpp b/apps/openmw/mwrender/animation.cpp
index 2279375c2..9fe9dd451 100644
--- a/apps/openmw/mwrender/animation.cpp
+++ b/apps/openmw/mwrender/animation.cpp
@@ -31,6 +31,8 @@
 #include "../mwbase/world.hpp"
 #include "../mwworld/esmstore.hpp"
 #include "../mwworld/class.hpp"
+#include "../mwworld/fallback.hpp"
+#include "../mwworld/cellstore.hpp"
 
 #include "../mwmechanics/character.hpp" // FIXME: for MWMechanics::Priority
 
@@ -1000,14 +1002,28 @@ namespace MWRender
         osg::Light* light = new osg::Light;
         lightSource->setLight(light);
 
-        float realRadius = esmLight->mData.mRadius;
+        const MWWorld::Fallback* fallback = MWBase::Environment::get().getWorld()->getFallback();
 
-        lightSource->setRadius(realRadius);
-        light->setLinearAttenuation(10.f/(esmLight->mData.mRadius*2.f));
-        //light->setLinearAttenuation(0.05);
-        light->setConstantAttenuation(0.f);
+        float radius = esmLight->mData.mRadius;
+        lightSource->setRadius(radius);
 
-        light->setDiffuse(SceneUtil::colourFromRGB(esmLight->mData.mColor));
+        static bool outQuadInLin = fallback->getFallbackBool("LightAttenuation_OutQuadInLin");
+        static bool useQuadratic = fallback->getFallbackBool("LightAttenuation_UseQuadratic");
+        static float quadraticValue = fallback->getFallbackFloat("LightAttenuation_QuadraticValue");
+        static float quadraticRadiusMult = fallback->getFallbackFloat("LightAttenuation_QuadraticRadiusMult");
+        static bool useLinear = fallback->getFallbackBool("LightAttenuation_UseLinear");
+        static float linearRadiusMult = fallback->getFallbackFloat("LightAttenuation_LinearRadiusMult");
+        static float linearValue = fallback->getFallbackFloat("LightAttenuation_LinearValue");
+
+        bool exterior = mPtr.isInCell() && mPtr.getCell()->getCell()->isExterior();
+
+        SceneUtil::configureLight(light, radius, exterior, outQuadInLin, useQuadratic, quadraticValue,
+                                  quadraticRadiusMult, useLinear, linearRadiusMult, linearValue);
+
+        osg::Vec4f diffuse = SceneUtil::colourFromRGB(esmLight->mData.mColor);
+        if (esmLight->mData.mFlags & ESM::Light::Negative)
+            diffuse *= -1;
+        light->setDiffuse(diffuse);
         light->setAmbient(osg::Vec4f(0,0,0,1));
         light->setSpecular(osg::Vec4f(0,0,0,0));
 
diff --git a/components/sceneutil/lightmanager.cpp b/components/sceneutil/lightmanager.cpp
index e53a55bf3..6040f9536 100644
--- a/components/sceneutil/lightmanager.cpp
+++ b/components/sceneutil/lightmanager.cpp
@@ -325,4 +325,28 @@ namespace SceneUtil
             traverse(node, nv);
     }
 
+    void configureLight(osg::Light *light, float radius, bool isExterior, bool outQuadInLin, bool useQuadratic,
+                        float quadraticValue, float quadraticRadiusMult, bool useLinear, float linearRadiusMult, float linearValue)
+    {
+        bool quadratic = useQuadratic && (!outQuadInLin || isExterior);
+
+        float quadraticAttenuation = 0;
+        float linearAttenuation = 0;
+        if (quadratic)
+        {
+            float r = radius * quadraticRadiusMult;
+            quadraticAttenuation = quadraticValue / std::pow(r, 2);
+        }
+        if (useLinear)
+        {
+            float r = radius * linearRadiusMult;
+            linearAttenuation = linearValue / r;
+        }
+
+        light->setLinearAttenuation(linearAttenuation);
+        light->setQuadraticAttenuation(quadraticAttenuation);
+        light->setConstantAttenuation(0.f);
+
+    }
+
 }
diff --git a/components/sceneutil/lightmanager.hpp b/components/sceneutil/lightmanager.hpp
index dd0c2d3e6..d5aecdbb6 100644
--- a/components/sceneutil/lightmanager.hpp
+++ b/components/sceneutil/lightmanager.hpp
@@ -124,6 +124,9 @@ namespace SceneUtil
         LightManager* mLightManager;
     };
 
+    /// @brief Configures a light's attenuation according to vanilla Morrowind attenuation settings.
+    void configureLight(osg::Light* light, float radius, bool isExterior, bool outQuadInLin, bool useQuadratic, float quadraticValue,
+                         float quadraticRadiusMult, bool useLinear, float linearRadiusMult, float linearValue);
 
 }